Hitherto, as described in Japanese Patent No. 5210117, there has been known a bumper device for a vehicle, which is configured to absorb a shock caused when the vehicle collides with an object. The bumper device for a vehicle (bumper reinforcement) includes a tubular portion formed into a tubular shape (hollow shape) extending in a vehicle width direction, and a reinforcing portion inserted into the tubular portion, which is configured to reinforce the tubular portion. The tubular portion has a substantially rectangular shape in cross-section taken along a direction perpendicular to a longitudinal direction of the tubular portion. That is, the tubular portion includes an upper wall portion and a lower wall portion each being formed into a plate-like shape extending perpendicularly to a vehicle height direction, a front wall portion connecting front ends of the upper wall portion and the lower wall portion, and a rear wall portion connecting rear ends of the upper wall portion and the lower wall portion. The tubular portion is made of metal. The tubular portion is manufactured by, for example, an extrusion molding method. The reinforcing portion includes an upper foamed resin (thermosetting foamed resin) arranged on an inner side surface of the tubular portion to extend in the vehicle width direction along a connecting portion (upper corner portion) between the upper wall portion and the front wall portion that construct the tubular portion, a lower foamed resin (thermosetting foamed resin) arranged to extend in the vehicle width direction along a connecting portion (lower corner portion) between the lower wall portion and the front wall portion, and a support member (carrier member) configured to support the upper foamed resin and the lower foamed resin.
When an object collides with the vehicle (bumper device), a significant load is applied particularly to the upper corner portion and the lower corner portion. In the bumper device described in Japanese Patent No. 5210117, the upper corner portion and the lower corner portion are reinforced with the upper foamed resin and the lower foamed resin, respectively. Thus, flexural rigidity of the bumper device for a vehicle is enhanced, thereby increasing a shock absorbing amount.
In the bumper device for a vehicle described in Japanese Patent No. 5210117, the upper corner portion and the lower corner portion are reinforced with the foamed resins, but flexural rigidity of the foamed resins is lower than flexural rigidity of the tubular portion. Accordingly, even when the upper corner portion and the lower corner portion are reinforced with the foamed resins, the flexural rigidity of the bumper device for a vehicle is only slightly enhanced, with the result that the shock absorbing amount is only slightly increased as well.